To prosper, the solitary animals of the jungle must ruthlessly pursue their own biological priorities. The social animals of the plain have the same drives but their brains must also identify situations where group interests override individual ones, and act accordingly.

Previous biographies have called almost everything about Bertolt Brecht, including his authorship of the works attributed to him, into doubt, while political changes have seemed to diminish his importance. But a new life, revealing a new Brecht, reasserts his importance.

‘The Hard Conversation’ is what happens when a doctor reveals to a patient the no longer avoidable truth. But perhaps society should also have a hard conversation about the limits of medical science and the desirability of providing not infinite life but a decent end of life.